Jul 28, 2010 2:54 PM

Peacock butterfly caterpillars (black, spiky) recently infested our golden hop. Since the plant is vigorous, we let the caterpillars be. After they had grown to full size, all abruptly departed to form pupas in unknown locations. All but one, which I caught in a jar.

The reason I'm writing is to check if it's still alive. It changed into a pupa on 14 July, which was initially light green. It's now two weeks later, and it's more of a pale khaki colour. It doesn't move when touched. The jar was never sealed.

How long does it normally take to complete metamorphosis? Any way of confirming whether it's alive or dead? My daughter (3) is getting very impatient.

It's not too late, in fact I'm seeing some fresh adult peacocks flying now. Although I've not bred peacocks I believe that, like most butterfly chrysalides, they will darken a day or so before emergence. You will need to make sure that it has something to climb up and hang on to while its wings expand (they need to hang their wings downward) so a jam jar is possibly not the best container to use. However I've never heard of peacocks on hops, they generally feed on nettles, so you may not get what you expect...

Thanks for the great answers! Although I can't mark this question answered yet, you've given me hope.

Clive: I trapped it when it was still a caterpillar, and it actually attached itself to the underside of the jar lid, so it's hanging down nicely. On mossywombat's first link, I see that hop is in fact listed as a foodplant.

mossywombat: thanks for the links! That's them all right.

I'll update this thread when I have a butterfly, or when I finally give up.

I said I'd update this thread when I finally gave up, and I'm afraid I have. The brown pupa eventually developed dark blotches, so we had to accept it had died. Here are some photos: http://www.flickr.com/photos/fjordaan/4961634980/ (I don't think I took any photos after it had turned brown, unfortunately. It was only this bright green for a few days.)

It may be that the humidity or temperature were too high, allowing it to become mouldy. Or it may be parasitised. I have heard estimates of as much as 80% of butterfly larvae fall victim to parasites, although my experience is rather less. Worth keeping it in a cool dry place until next spring. You could put it in the garden shed in a box covered with netting (ensures airflow).